plants response to water and temperature Flashcards
How do plants respond to water availability?
Plants regulate water uptake and loss through stomata. When water is scarce, stomata close to minimize water loss. When water is plentiful, stomata open to allow gas exchange and photosynthesis.
a behavior where plants adjust their root growth to seek out water sources, growing roots toward areas with more water availability.
Hydrotropism
the opening and closing of stomata (pores on leaves) that control the rate of water evaporation and gas exchange.
stomatal regulation
the pressure exerted by the cell membrane against the cell wall when a plant is well-hydrated. It provides structural support, helping the plant stand upright and preventing wilting.
Turgor pressure
What happens to plants when they experience water stress?
When experiencing water stress, plants may wilt due to reduced turgor pressure, causing leaves to droop as they lose structural support.
How do plant hormones respond to water stress?
Plant hormones like abscisic acid (ABA) play a role in signaling water stress and triggering stomatal closure, reducing water loss through transpiration.
How does temperature affect enzyme activity in plants?
As temperature increases, plant enzymes function faster, leading to increased growth and metabolic activity. However, extreme heat can denature enzymes, reducing plant function.
How do plants regulate water loss in hot weather?
In hot weather, plants close their stomata to prevent excessive water loss through transpiration, helping them conserve water.
How do plants adjust leaf orientation in response to temperature?
Plants can adjust leaf angles to optimize sunlight exposure and minimize heat absorption in high temperatures, helping to prevent overheating.
How does temperature affect flowering time in plants?
Warmer temperatures often trigger earlier blooming in plants. Temperature significantly influences the timing of flowering for many species.
How does temperature influence seed germination?
Different plant species have specific temperature requirements for seed germination. If temperatures are not within the optimal range, germination may be delayed or prevented.
How do plants adapt to temperature fluctuations?
Plants alter their cell membrane fluidity and protein structure to tolerate temperature fluctuations, ensuring that cellular functions continue under varying conditions.
the process by which plants change their cell structure in response to extreme temperatures, helping them cope with environmental temperature changes.
Thermomorphogenesis
Why are water and temperature crucial for plant growth and development?
water and temperature are key environmental factors that influence processes like photosynthesis, transpiration, germination, and flowering. Plants require adequate water and favorable temperatures to thrive, with deviations leading to stress and reduced growth.
What role do stomata play in transpiration in plants?
Stomata are small pores on plant leaves that allow for gas exchange (carbon dioxide in, oxygen out). They also regulate water loss through transpiration, a process where water vapor is released into the atmosphere.
How do plants control water loss during dry conditions?
During dry conditions, plants close their stomata to reduce water loss through transpiration, conserving water and preventing dehydration.
How do roots help plants acquire water?
Plants adjust their root architecture to grow towards areas with more water availability. This behavior, known as hydrotropism, ensures that roots are optimized for water acquisition.
How does extreme heat affect plant growth?
Extreme heat can increase metabolic activity in plants initially, but if the temperature rises too much, it can denature enzymes, disrupt cellular functions, and hinder plant growth.
How do plants use leaf orientation to avoid heat stress?
Plants can adjust the angle of their leaves to minimize direct sunlight exposure and reduce heat absorption, helping them manage high temperatures and avoid excessive heat stress.
How does temperature affect photosynthesis in plants?
Photosynthesis is temperature-dependent. As temperature increases, photosynthesis can occur more rapidly until an optimal temperature is reached. Beyond that, enzymes involved in photosynthesis can become denatured, reducing the plant’s ability to photosynthesize.
How does temperature affect plant respiration?
As temperature increases, plant respiration rates increase, leading to more energy production. However, at higher temperatures, excessive respiration can deplete stored energy reserves and harm plant health.
What happens to plant enzymes at high temperatures?
High temperatures can cause plant enzymes to become denatured (lose their shape), impairing their function and potentially slowing down critical processes like photosynthesis and growth.
How does temperature influence flowering in plants?
Temperature can affect the timing of flowering. Warmer temperatures often trigger early blooming, while cooler temperatures may delay or prevent flowering, depending on the plant species.
What happens to plant cells during water stress?
During water stress, cells experience a drop in turgor pressure, leading to wilting and reduced cell function. This can slow down metabolic processes and stunt plant growth.
What role does the plant hormone ABA (abscisic acid) play during water stress?
ABA is involved in signaling water stress in plants. It triggers the closure of stomata to conserve water and prevent excessive loss during dry conditions.
